MXPA97008231A - Articula implants - Google Patents

Abstract

A connector (110) for connecting adjacent areas of adjacent segments (102) of an articulated implant, the connector includes a plurality of flexible joints (112), wherein each flexible joint includes a plurality of portions with each pair of abutting portions having an area of inflection between them and where during the expansion of said implant, the area of inflexion of each flexible joint remains inflexed

Description

ARTICULATED IMPLANTS FIELD AND BACKGROUND OF THE INVENTION The present invention relates to implants that are implanted as part of a procedure of the balloon angioplasty procedure within a body conduit of a living animal or a human being to maintain the opening. In particular, the present invention relates to intravascular articulated implants for delivery through or implantation in a blood vessel having a curved portion. Intravascular implants having a restricted diameter for delivery through a blood vessel and an expanded diameter to apply a force that extends outwardly to support the blood vessel are known in the art Articulated intravascular implants for delivery through a blood vessel bent or implanted therein are also known in the art Self-expanding articulated implants, for example, in U.S. Patent No. 5,104,404 entitled "Articulated Stent" for Wolff Articulated implants The expandable ones are commercially available under the trade name Palmaz-Schatz Ballon-Expandable Stents from Johnson & Johnson Intervention Systems Co An auto-expandable articulated implant implant 10 deployed in a curved blood vessel 16 is now described with reference to Figure 1 which is, in fact, Figure 2 of the aforementioned U.S. Patent No. 5,104,404 . The implant 10 is formed of a number of individual segments 12 hinged by hinges 14 connected at each end to the segments 12. The implant 10 is preferably manufactured from the shape memory material, for example, nitinol and as such is expandable after of the supply from a delivery system described in U.S. Patent No. 4,830,003 to Wolff et al. However, those articular intravascular implants of the prior art suffer from a number of disadvantages both during delivery through a curved blood vessel and when implanted therein as will now be described. The delivery of the implant 10 through the curved blood vessel 16 is more complicated than the delivery of a non-articulated implant in which the implant 10 has to be angularly oriented so that its hinges 14 are located towards the convex portion of the blood vessel 16 of so that the implant 10 can be fixed inwards. In the present example, it will be noted that the hinges 14 are located on the same side of the segments 12 because the blood vessel 16 has only a single curve in a plane. It can be appreciated that the delivery of implants through blood vessels having one or more curved portions that are not in the same plane is even more complicated and generally requires specially constructed implants. Even when implanted in a curved blood vessel 16, the implants 10 shown to be missing in the spaces between the segments 12 leave the curved portion of the blood vessel 16 without support. Furthermore, the spaces in the convex portion of the blood vessel 16 are substantially larger than the spaces in the concave portion thereof, thereby inducing non-uniform and therefore undesirable stresses on the blood vessel 16. Therefore, it would be highly desirable to have an articulated implant that does not require any particular angular orientation when It is supplying through a curved body duct and provides continuous and uniform support for the straight and curved portions of a body duct when implanted. It would be highly desirable that the structure of an implant does not depend on particular orientations of the curved portions of the blood vessel.

BRIEF DESCRIPTION OF THE INVENTION The object of the present invention is an articulated implant that can be delivered through a bent body conduit using a routine medical procedure and a conventional implant delivery system. further, the implant provides continuous and uniform support for the straight and curved portions of a body duct when implanted. In addition, the structure of an implant and its support of a body duct do not depend on the orientations of the curved portions of the duct. The object of the present invention is achieved by an articulated implant, comprising: (a) at least two substantially rigid segments; and (b) a flexible connector for connecting adjacent segments, wherein the connector assumes a substantially cylindrical configuration when relaxed and a curved configuration extended and differentially compressed when flexed. After expansion, the rigid segments of the implant preferably have a fine diamond-shaped mesh having sides 1 mm long to provide continuous and uniform support for vertical portions of a body duct. The connectors can be implemented as a plurality of substantially helical links connecting adjacent segments. Alternatively, the connectors can be implemented as links each having at least one twist. The connectors have between 8-24 links to provide continuous and uniform support to both the straight and curved portions of a body canal. Implants have restricted diameters for intraluminal delivery and are then deformed, by inflation of a balloon that is part of your catheter delivery system, to expanded diameters to apply forces that extend radially outward to support the lumen of the body's ducts. . The restricted and expanded diameters of the implants typically remain at the scales of 1.0-3.5 and 3.5-10.0 mm, respectively. The implants are preferably manufactured from biocompatible materials of low memory, more plastics than elastic, for example, stainless steel 316L, gold, tantalum, etc., which allows them to be plastically deformed from their diameters restricted to their expanded diameters. A typical implant for implantation in a human coronary artery is 9-24 mm long comprising three to seven 2.2 mm long implant segments connected by two to six 1 mm long connectors so that the ends of the implant subtended between an angle of 45 ° to 135 ° in a radius of curvature of about 9 mm when flexed.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is described herein, by way of example only, with reference to the accompanying drawings, wherein: Fig. 1 shows an approaching view of a prior art articulated implant deployed in a curved blood vessel; 2a and 2b show a preferred embodiment of an articulated implant, constructed and operative in accordance with the teachings of the present invention, in its relaxed and flexed states prior to plastic deformation; Fig. 2c shows the extended implant of Fig. 2 after plastic deformation; Fig. 2d shows the implant of Fig. 2 mounted on a catheter in its flexed state; Figs. 2e and 2f show the implant of Fig. 2 before and after expansion by a balloon that is part of its catheter delivery system; Figs. 3a and 3b show a second embodiment of an articulated implant constructed and operative in accordance with the teachings of the present invention, in its relaxed and flexed states prior to plastic deformation; and La 3c shows the extended implant of Fig. 3 after plastic deformation.

DESCRIPTION OF THE PREFERRED MODALITIES The present invention is of an articulated implant for delivery through a bent body conduit, for example, a peripheral or coronary artery of a living animal or human being and implantation therein as part of a balloon angioplasty procedure to maintain The opening.

The principles and operation of the articulated implant of the present invention can be better understood with reference to the drawings and the appended description. Referring now to the drawings, Figs. 2a-2c show an articulated implant, generally designated 100, constructed or operative in accordance with the teachings of the present invention, generally comprising a number of substantially rigid segments 102 connected by connectors 110. Segments 102 are preferably shaped to present a mesh of fine diamond of interconnected diamond-shaped cells 108 having sides of 1 mm in expansion as seen in Figure 2c. Depending on the predetermined diameter of the implant 100, segments 102 typically comprise between 8-24 diamond-shaped cells 108. The connectors 110 comprise links 112 connecting a front end 104 to a rearward end 106 of the adjacent segments 102. The links 112 are preferably extend in a helical fashion between the vertices of the diamond-shaped cells 108 at the front and rear ends 104 and 106 of the adjacent segments 102 so that the number of links 112 equals the number of cells 108. The links 112 are preferably uniformly deployed around the perimeters of the segments 102 so that the connectors 110 can flex in the same manner in any direction and to provide uniform and continuous support to the straight and curved portions of a body duct. Alternating connectors 110 at the front and rear ends 104 and 106, respectively, of a segment 102 preferably have links 112 wound in right and left directions. The alternate coiled connectors 110 ensure that the rotational displacement of the links 112 and adjacent segments 102 relative to the walls of a blood vessel and more importantly the balloon of its delivery system are minimized when the implant is expanded. It is a particular feature of the present invention that the connectors 110 have a generally cylindrical configuration when the implant 100 is relaxed as best seen in Figure 2a and a curved configuration stretched and compressed differently when the implant 100 is flexed as shown. see better in Figure 2b. The flexed configuration is carried by approximately two relatively opposite link shifts 112. First differential stretching of the connectors occurs at the convex portion thereof denoted 114 by links 112 that are offset one away from the other. Second, the differential compression of the connectors 110 occurs in the concave portion thereof denoted 116 by the links 112 that are displaced towards each other.

The implant 100 has a restricted diameter for delivery through a bent body passageway as shown in Figs. 2a and 2b and an expanded diameter as shown in Figure 2c to support the body duct. The implant 100 is preferably manufactured from a biocompatible lower memory material, more plastic than elastic, for example, 316L stainless steel, gold, tantalum, etc., which allows it to deform plastically from its restricted diameter to its expanded diameter. The restricted and expanded diameters of the implant 100 typically remain at the scales of 1.0-3.5 mm and 3.5-10.0 mm, respectively. With reference now to Figs. 2d-2f, the implant 100 is shown extending over a balloon 118 that is part of the catheter delivery system 120. The implant 100 is mounted on the catheter delivery system 120 in its restricted diameter condition shown in FIG. 2e for plastic deformation through balloon inflation 118 to its expanded diameter shown in Fig. 2f to support the walls of a body duct. An illustrative implant for implantation in a human coronary artery is typically 15 mm long shaped up to five 2.2 mm long segments connected by connectors 110 of 1 mm length and capable of bending so that their ends are subtended a 90 ° angle at a radius of curvature of approximately 9 mm.

The delivery of the articulated implant 100 is considerably simpler than the delivery of the articulated implant of the prior art 10 since the implant 100 is equally flexible in all directions and therefore does not require a dedicated angular orientation to pass a particular curved portion. This advantage is particularly important for delivery through blood vessels having multiple curved portions. It is a further advantage of the implant 100 over the prior art implants 10, that the implant 100 provides continuous and uniform support along the entire length of a blood vessel by means of the non-flexed segments 102 and connectors 110 that support the straight portions thereof while the connector portions 114 and 116 support convex and curved portions thereof. respectively. With reference now to Figs. 3a and 3b, an articulated implant 122 is shown in which the connectors 124 comprise links 126 having one or more folds 128. The design of connectors 124 refers to that of the connector 110 since the implant 100 may have a tendency to rupture the balloon 118 due to two reasons First. The links 112 extend over the portion of the balloon 118 having a tendency to deviate inwardly when the implant 100 is flexed. Second, the segments 102 exhibit a rotational displacement relative to the balloon 118 when the implant 100 expands.

In this case, the differential curved extended and compressed configuration of the connector 124 is effected by approximately two relatively opposite displacements of links 112 as before except that the differential stretching of the connectors 124 in the convex portion 114 occurs through the folds 128 that are of some type. In this manner, the differential compression of the connectors 124 in the concave portion 116 occurs through the bends 128 that are flexed more accurately. In a manner similar to implant 100, implant 122 has a restricted diameter for delivery through a bent body conduit as shown in Fig. 3a and 3b and an expanded diameter as shown in Fig. 3c to support a body duct when implanted in it. While this invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention can be made.

Claims (8)

1. A connector for connecting adjacent areas of adjacent segments of an articulated implant, the connector comprising: a plurality of flexible links, wherein each of the flexible links includes a plurality of portions with each pair of nearby portions having an inflection area between them.

A connector according to claim 1, wherein, during the expansion of the implant, the inflection area of each flexible link remains flexed.

3. An articulated implant, comprising: a) at least two substantially rigid segments having a plurality of connected cells each having vertices, wherein, upon expansion, each of the rigid segments presents a diamond mesh substantially Cylindrical and b) a flexible connector, comprising a plurality of flexible links wherein each of the flexible links connects the vertices of adjacent cells on the adjacent rigid segments; each of the flexible links includes a plurality of portions with each pair of nearby portions having an area of inflection therebetween, and during the expansion of the implant, the inflection area remains flexed.

4. The implant as in claim 3, wherein the plurality of links includes between 8-24 links.

5. The implant as in claim 3, made of biocompatible material capable of more plastic than elastic deformation.

6. The implant as in claim 5, wherein the material is stainless steel.

7. The implant as in claim 5, wherein the material is gold.

8. The implant as in claim 5, wherein the material is tantalum.